Having Kids Lowers Men's Testosterone

A new study shows that having a baby lowers men's testosterone levels. However, this doesn't mean they're turning into sissies.

According to the Times, researches studied 600 Filipino men over the course of several years. The men who had children experienced a drop in testosterone much greater than those who didn't (testosterone falls with time in most men). And the men who spent the most time with their kids had the biggest drop. Previous studies had found that dads had lower levels of the hormone than non-dads, but scientists weren't sure whether men with lower testosterone were simply more likely to have kids. The Filipino study shows this isn't the case — men who reproduced actually had higher initial levels. So something about taking care of babies causes these levels to fall.

The stereotypical interpretation of this would be that fatherhood unmans men or makes them somehow soft. However, anthropologist Carol Worthman tells the Times, "we're not talking about changes that are going to take testosterone outside the range of having hairy chests, deep voices and big muscles and sperm counts. These are more subtle effects." And rather than showing that fatherhood is for sissies, these results may show that fatherhood is for, well, men. Says study coauthor Lee Gettler,

[T]his should be viewed as, ‘Oh it's great, women aren't the only ones biologically adapted to be parents.' Humans give birth to incredibly dependent infants. Historically, the idea that men were out clubbing large animals and women were staying behind with babies has been largely discredited. The only way mothers could have highly needy offspring every couple of years is if they were getting help.

Some evolutionary psychologists claim that women are hardwired for parenting and thus always more fit for the task. And while the testosterone study doesn't prove the existence of hardwiring for either sex, it does show that women aren't the only ones to experience bodily changes surrounding the birth of a child. This should serve as ammunition against those who claim that raising kids is always women's work.

In Study, Fatherhood Leads To Drop In Testosterone [NYT]

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